For many Angelenos, the spectacle of armed federal agents — faces hidden behind neck gaiters and balaclavas — jumping out of unmarked vans to snatch people off the streets presents a clear threat to public safety.As federal immigration agents have ratcheted up enforcement raids, arresting and detaining anyone they suspect of violating immigration laws, critics warn their tactic of masking — particularly when wearing plain clothes and no visible marker of identity — spreads fear and panic across communities and imperils citizens as well as immigrants without legal status.“It’s very dangerous,” said Scott Shuchart, who worked for the U.S. Immigration...